Merge pull request #72364 from slavapestov/fix-rdar124498054

AST: Refine name lookup rule for protocol extension 'where' clauses

Author: slavapestov

include/swift/AST/ASTScope.h

@@ -482,45 +482,33 @@ class Portion : public ASTAllocated<ASTScopeImpl> {
 
   virtual NullablePtr<ASTScopeImpl>
   insertionPointForDeferredExpansion(IterableTypeScope *) const = 0;
-  };
-
-  // For the whole Decl scope of a GenericType or an Extension
-  class GenericTypeOrExtensionWholePortion final : public Portion {
-  public:
-    GenericTypeOrExtensionWholePortion() : Portion("Decl") {}
-    virtual ~GenericTypeOrExtensionWholePortion() {}
-
-    // Just for TypeAlias
-    ASTScopeImpl *expandScope(GenericTypeOrExtensionScope *,
-                              ScopeCreator &) const override;
+};
 
-    SourceRange getChildlessSourceRangeOf(const GenericTypeOrExtensionScope *,
-                                          bool omitAssertions) const override;
+// For the whole Decl scope of a GenericType or an Extension
+class GenericTypeOrExtensionWholePortion final : public Portion {
+public:
+  GenericTypeOrExtensionWholePortion() : Portion("Decl") {}
+  virtual ~GenericTypeOrExtensionWholePortion() {}
 
-    NullablePtr<const ASTScopeImpl>
-    getLookupLimitFor(const GenericTypeOrExtensionScope *) const override;
+  // Just for TypeAlias
+  ASTScopeImpl *expandScope(GenericTypeOrExtensionScope *,
+                            ScopeCreator &) const override;
 
-    NullablePtr<ASTScopeImpl>
-    insertionPointForDeferredExpansion(IterableTypeScope *) const override;
-  };
+  SourceRange getChildlessSourceRangeOf(const GenericTypeOrExtensionScope *,
+                                        bool omitAssertions) const override;
 
-  /// GenericTypeOrExtension = GenericType or Extension
-  class GenericTypeOrExtensionWhereOrBodyPortion : public Portion {
-  public:
-    GenericTypeOrExtensionWhereOrBodyPortion(const char *n) : Portion(n) {}
-    virtual ~GenericTypeOrExtensionWhereOrBodyPortion() {}
+  NullablePtr<const ASTScopeImpl>
+  getLookupLimitFor(const GenericTypeOrExtensionScope *) const override;
 
-    bool lookupMembersOf(const GenericTypeOrExtensionScope *scope,
-                         ASTScopeImpl::DeclConsumer consumer) const override;
+  NullablePtr<ASTScopeImpl>
+  insertionPointForDeferredExpansion(IterableTypeScope *) const override;
 };
 
 /// Behavior specific to representing the trailing where clause of a
 /// GenericTypeDecl or ExtensionDecl scope.
-class GenericTypeOrExtensionWherePortion final
-    : public GenericTypeOrExtensionWhereOrBodyPortion {
+class GenericTypeOrExtensionWherePortion final : public Portion {
 public:
-  GenericTypeOrExtensionWherePortion()
-      : GenericTypeOrExtensionWhereOrBodyPortion("Where") {}
+  GenericTypeOrExtensionWherePortion() : Portion("Where") {}
 
   bool lookupMembersOf(const GenericTypeOrExtensionScope *scope,
                        ASTScopeImpl::DeclConsumer consumer) const override;
@@ -537,11 +525,12 @@ class GenericTypeOrExtensionWherePortion final
 
 /// Behavior specific to representing the Body of a NominalTypeDecl or
 /// ExtensionDecl scope
-class IterableTypeBodyPortion final
-    : public GenericTypeOrExtensionWhereOrBodyPortion {
+class IterableTypeBodyPortion final : public Portion {
 public:
-  IterableTypeBodyPortion()
-      : GenericTypeOrExtensionWhereOrBodyPortion("Body") {}
+  IterableTypeBodyPortion() : Portion("Body") {}
+
+  bool lookupMembersOf(const GenericTypeOrExtensionScope *scope,
+                       ASTScopeImpl::DeclConsumer consumer) const override;
 
   ASTScopeImpl *expandScope(GenericTypeOrExtensionScope *,
                             ScopeCreator &) const override;

include/swift/AST/Decl.h

@@ -32,7 +32,6 @@
 #include "swift/AST/IfConfigClause.h"
 #include "swift/AST/Import.h"
 #include "swift/AST/Initializer.h"
-#include "swift/AST/InverseMarking.h"
 #include "swift/AST/LayoutConstraint.h"
 #include "swift/AST/LifetimeAnnotation.h"
 #include "swift/AST/ReferenceCounting.h"
@@ -96,7 +95,6 @@ namespace swift {
   class NamedPattern;
   class EnumCaseDecl;
   class EnumElementDecl;
-  struct InverseMarking;
   class ParameterList;
   class ParameterTypeFlags;
   class Pattern;

include/swift/AST/InverseMarking.h

@@ -247,6 +247,9 @@ enum class UnqualifiedLookupFlags {
   MacroLookup            = 1 << 7,
   /// This lookup should only return modules
   ModuleLookup           = 1 << 8,
+  /// This lookup should discard 'Self' requirements in protocol extension
+  /// 'where' clauses.
+  DisregardSelfBounds    = 1 << 9
 };
 
 using UnqualifiedLookupOptions = OptionSet<UnqualifiedLookupFlags>;

include/swift/AST/NameLookup.h

@@ -137,10 +137,6 @@ class alignas(1 << TypeReprAlignInBits) TypeRepr
   /// Is this type representation a protocol?
   bool isProtocolOrProtocolComposition(DeclContext *dc);
 
-  /// Is this `~<target>` representation.
-  bool isInverseOf(InvertibleProtocolKind target,
-                   DeclContext *dc);
-
   /// Is this type representation known to be invalid?
   bool isInvalid() const { return Bits.TypeRepr.Invalid; }
 

include/swift/AST/TypeRepr.h

@@ -29,7 +29,6 @@
 #include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/GenericParamList.h"
 #include "swift/AST/GenericSignature.h"
-#include "swift/AST/InverseMarking.h"
 #include "swift/AST/MacroDefinition.h"
 #include "swift/AST/Module.h"
 #include "swift/AST/NameLookup.h"

lib/AST/ASTPrinter.cpp

@@ -274,22 +274,24 @@ bool Portion::lookupMembersOf(const GenericTypeOrExtensionScope *,
   return false;
 }
 
-bool GenericTypeOrExtensionWhereOrBodyPortion::lookupMembersOf(
+bool GenericTypeOrExtensionWherePortion::lookupMembersOf(
     const GenericTypeOrExtensionScope *scope,
     ASTScopeImpl::DeclConsumer consumer) const {
   if (scope->getCorrespondingNominalTypeDecl().isNull())
     return false;
+
+  if (!scope->areMembersVisibleFromWhereClause())
+    return false;
+
   return consumer.lookInMembers(scope->getGenericContext());
 }
 
-bool GenericTypeOrExtensionWherePortion::lookupMembersOf(
+bool IterableTypeBodyPortion::lookupMembersOf(
     const GenericTypeOrExtensionScope *scope,
     ASTScopeImpl::DeclConsumer consumer) const {
-  if (!scope->areMembersVisibleFromWhereClause())
+  if (scope->getCorrespondingNominalTypeDecl().isNull())
     return false;
-
-  return GenericTypeOrExtensionWhereOrBodyPortion::lookupMembersOf(
-    scope, consumer);
+  return consumer.lookInMembers(scope->getGenericContext());
 }
 
 bool GenericTypeOrExtensionScope::areMembersVisibleFromWhereClause() const {

lib/AST/ASTScopeLookup.cpp

@@ -32,7 +32,6 @@
 #include "swift/AST/GenericSignature.h"
 #include "swift/AST/ImportCache.h"
 #include "swift/AST/Initializer.h"
-#include "swift/AST/InverseMarking.h"
 #include "swift/AST/LazyResolver.h"
 #include "swift/AST/MacroDefinition.h"
 #include "swift/AST/MacroDiscriminatorContext.h"
@@ -6615,42 +6614,6 @@ bool ProtocolDecl::inheritsFrom(const ProtocolDecl *super) const {
   return (llvm::find(allInherited, super) != allInherited.end());
 }
 
-static void findInheritedType(
-    InheritedTypes inherited,
-    llvm::function_ref<bool(Type, NullablePtr<TypeRepr>)> isMatch) {
-  for (size_t i = 0; i < inherited.size(); i++) {
-    auto type = inherited.getResolvedType(i, TypeResolutionStage::Structural);
-    if (!type)
-      continue;
-
-    if (isMatch(type, inherited.getTypeRepr(i)))
-      break;
-  }
-}
-
-static InverseMarking::Mark
-findInverseInInheritance(InheritedTypes inherited,
-                         InvertibleProtocolKind target) {
-  auto isInverseOfTarget = [&](Type t) {
-    if (auto pct = t->getAs<ProtocolCompositionType>())
-      return pct->getInverses().contains(target);
-    return false;
-  };
-
-  InverseMarking::Mark inverse;
-  findInheritedType(inherited,
-                    [&](Type inheritedTy, NullablePtr<TypeRepr> repr) {
-                      if (!isInverseOfTarget(inheritedTy))
-                        return false;
-
-                      inverse = InverseMarking::Mark(
-                          InverseMarking::Kind::Explicit,
-                          repr.isNull() ? SourceLoc() : repr.get()->getLoc());
-                      return true;
-                    });
-  return inverse;
-}
-
 bool ProtocolDecl::requiresClass() const {
   return evaluateOrDefault(getASTContext().evaluator,
     ProtocolRequiresClassRequest{const_cast<ProtocolDecl *>(this)}, false);